libavcodec/rpza.c

   1 /*
   2  * Quicktime Video (RPZA) Video Decoder
   3  * Copyright (C) 2003 the ffmpeg project
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file rpza.c
  24  * QT RPZA Video Decoder by Roberto Togni <rtogni@bresciaonline.it>
  25  * For more information about the RPZA format, visit:
  26  *   http://www.pcisys.net/~melanson/codecs/
  27  *
  28  * The RPZA decoder outputs RGB555 colorspace data.
  29  *
  30  * Note that this decoder reads big endian RGB555 pixel values from the
  31  * bytestream, arranges them in the host's endian order, and outputs
  32  * them to the final rendered map in the same host endian order. This is
  33  * intended behavior as the ffmpeg documentation states that RGB555 pixels
  34  * shall be stored in native CPU endianness.
  35  */
  36
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <unistd.h>
  41
  42 #include "avcodec.h"
  43
  44 typedef struct RpzaContext {
  45
  46     AVCodecContext *avctx;
  47     AVFrame frame;
  48
  49     const unsigned char *buf;
  50     int size;
  51
  52 } RpzaContext;
  53
  54 #define ADVANCE_BLOCK() \
  55 { \
  56     pixel_ptr += 4; \
  57     if (pixel_ptr >= width) \
  58     { \
  59         pixel_ptr = 0; \
  60         row_ptr += stride * 4; \
  61     } \
  62     total_blocks--; \
  63     if (total_blocks < 0) \
  64     { \
  65         av_log(s->avctx, AV_LOG_ERROR, "warning: block counter just went negative (this should not happen)\n"); \
  66         return; \
  67     } \
  68 }
  69
  70 static void rpza_decode_stream(RpzaContext *s)
  71 {
  72     int width = s->avctx->width;
  73     int stride = s->frame.linesize[0] / 2;
  74     int row_inc = stride - 4;
  75     int stream_ptr = 0;
  76     int chunk_size;
  77     unsigned char opcode;
  78     int n_blocks;
  79     unsigned short colorA = 0, colorB;
  80     unsigned short color4[4];
  81     unsigned char index, idx;
  82     unsigned short ta, tb;
  83     unsigned short *pixels = (unsigned short *)s->frame.data[0];
  84
  85     int row_ptr = 0;
  86     int pixel_ptr = 0;
  87     int block_ptr;
  88     int pixel_x, pixel_y;
  89     int total_blocks;
  90
  91     /* First byte is always 0xe1. Warn if it's different */
  92     if (s->buf[stream_ptr] != 0xe1)
  93         av_log(s->avctx, AV_LOG_ERROR, "First chunk byte is 0x%02x instead of 0xe1\n",
  94             s->buf[stream_ptr]);
  95
  96     /* Get chunk size, ingnoring first byte */
  97     chunk_size = AV_RB32(&s->buf[stream_ptr]) & 0x00FFFFFF;
  98     stream_ptr += 4;
  99
 100     /* If length mismatch use size from MOV file and try to decode anyway */
 101     if (chunk_size != s->size)
 102         av_log(s->avctx, AV_LOG_ERROR, "MOV chunk size != encoded chunk size; using MOV chunk size\n");
 103
 104     chunk_size = s->size;
 105
 106     /* Number of 4x4 blocks in frame. */
 107     total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4);
 108
 109     /* Process chunk data */
 110     while (stream_ptr < chunk_size) {
 111         opcode = s->buf[stream_ptr++]; /* Get opcode */
 112
 113         n_blocks = (opcode & 0x1f) + 1; /* Extract block counter from opcode */
 114
 115         /* If opcode MSbit is 0, we need more data to decide what to do */
 116         if ((opcode & 0x80) == 0) {
 117             colorA = (opcode << 8) | (s->buf[stream_ptr++]);
 118             opcode = 0;
 119             if ((s->buf[stream_ptr] & 0x80) != 0) {
 120                 /* Must behave as opcode 110xxxxx, using colorA computed
 121                  * above. Use fake opcode 0x20 to enter switch block at
 122                  * the right place */
 123                 opcode = 0x20;
 124                 n_blocks = 1;
 125             }
 126         }
 127
 128         switch (opcode & 0xe0) {
 129
 130         /* Skip blocks */
 131         case 0x80:
 132             while (n_blocks--) {
 133               ADVANCE_BLOCK();
 134             }
 135             break;
 136
 137         /* Fill blocks with one color */
 138         case 0xa0:
 139             colorA = AV_RB16 (&s->buf[stream_ptr]);
 140             stream_ptr += 2;
 141             while (n_blocks--) {
 142                 block_ptr = row_ptr + pixel_ptr;
 143                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 144                     for (pixel_x = 0; pixel_x < 4; pixel_x++){
 145                         pixels[block_ptr] = colorA;
 146                         block_ptr++;
 147                     }
 148                     block_ptr += row_inc;
 149                 }
 150                 ADVANCE_BLOCK();
 151             }
 152             break;
 153
 154         /* Fill blocks with 4 colors */
 155         case 0xc0:
 156             colorA = AV_RB16 (&s->buf[stream_ptr]);
 157             stream_ptr += 2;
 158         case 0x20:
 159             colorB = AV_RB16 (&s->buf[stream_ptr]);
 160             stream_ptr += 2;
 161
 162             /* sort out the colors */
 163             color4[0] = colorB;
 164             color4[1] = 0;
 165             color4[2] = 0;
 166             color4[3] = colorA;
 167
 168             /* red components */
 169             ta = (colorA >> 10) & 0x1F;
 170             tb = (colorB >> 10) & 0x1F;
 171             color4[1] |= ((11 * ta + 21 * tb) >> 5) << 10;
 172             color4[2] |= ((21 * ta + 11 * tb) >> 5) << 10;
 173
 174             /* green components */
 175             ta = (colorA >> 5) & 0x1F;
 176             tb = (colorB >> 5) & 0x1F;
 177             color4[1] |= ((11 * ta + 21 * tb) >> 5) << 5;
 178             color4[2] |= ((21 * ta + 11 * tb) >> 5) << 5;
 179
 180             /* blue components */
 181             ta = colorA & 0x1F;
 182             tb = colorB & 0x1F;
 183             color4[1] |= ((11 * ta + 21 * tb) >> 5);
 184             color4[2] |= ((21 * ta + 11 * tb) >> 5);
 185
 186             while (n_blocks--) {
 187                 block_ptr = row_ptr + pixel_ptr;
 188                 for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 189                     index = s->buf[stream_ptr++];
 190                     for (pixel_x = 0; pixel_x < 4; pixel_x++){
 191                         idx = (index >> (2 * (3 - pixel_x))) & 0x03;
 192                         pixels[block_ptr] = color4[idx];
 193                         block_ptr++;
 194                     }
 195                     block_ptr += row_inc;
 196                 }
 197                 ADVANCE_BLOCK();
 198             }
 199             break;
 200
 201         /* Fill block with 16 colors */
 202         case 0x00:
 203             block_ptr = row_ptr + pixel_ptr;
 204             for (pixel_y = 0; pixel_y < 4; pixel_y++) {
 205                 for (pixel_x = 0; pixel_x < 4; pixel_x++){
 206                     /* We already have color of upper left pixel */
 207                     if ((pixel_y != 0) || (pixel_x !=0)) {
 208                         colorA = AV_RB16 (&s->buf[stream_ptr]);
 209                         stream_ptr += 2;
 210                     }
 211                     pixels[block_ptr] = colorA;
 212                     block_ptr++;
 213                 }
 214                 block_ptr += row_inc;
 215             }
 216             ADVANCE_BLOCK();
 217             break;
 218
 219         /* Unknown opcode */
 220         default:
 221             av_log(s->avctx, AV_LOG_ERROR, "Unknown opcode %d in rpza chunk."
 222                  " Skip remaining %d bytes of chunk data.\n", opcode,
 223                  chunk_size - stream_ptr);
 224             return;
 225         } /* Opcode switch */
 226     }
 227 }
 228
 229 static av_cold int rpza_decode_init(AVCodecContext *avctx)
 230 {
 231     RpzaContext *s = avctx->priv_data;
 232
 233     s->avctx = avctx;
 234     avctx->pix_fmt = PIX_FMT_RGB555;
 235
 236     s->frame.data[0] = NULL;
 237
 238     return 0;
 239 }
 240
 241 static int rpza_decode_frame(AVCodecContext *avctx,
 242                              void *data, int *data_size,
 243                              const uint8_t *buf, int buf_size)
 244 {
 245     RpzaContext *s = avctx->priv_data;
 246
 247     s->buf = buf;
 248     s->size = buf_size;
 249
 250     s->frame.reference = 1;
 251     s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
 252     if (avctx->reget_buffer(avctx, &s->frame)) {
 253         av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
 254         return -1;
 255     }
 256
 257     rpza_decode_stream(s);
 258
 259     *data_size = sizeof(AVFrame);
 260     *(AVFrame*)data = s->frame;
 261
 262     /* always report that the buffer was completely consumed */
 263     return buf_size;
 264 }
 265
 266 static av_cold int rpza_decode_end(AVCodecContext *avctx)
 267 {
 268     RpzaContext *s = avctx->priv_data;
 269
 270     if (s->frame.data[0])
 271         avctx->release_buffer(avctx, &s->frame);
 272
 273     return 0;
 274 }
 275
 276 AVCodec rpza_decoder = {
 277     "rpza",
 278     CODEC_TYPE_VIDEO,
 279     CODEC_ID_RPZA,
 280     sizeof(RpzaContext),
 281     rpza_decode_init,
 282     NULL,
 283     rpza_decode_end,
 284     rpza_decode_frame,
 285     CODEC_CAP_DR1,
 286     .long_name = "QuickTime video (RPZA)",
 287 };